Lampholder with multiple arrangement of components



Dec. 24, 1968 E. J. MCLAUGHLIN LAMPHOLDER WITH MULTIPLE ARRANGEMENT OF COMPONENTS Filed Jan. 12, 1967 5 Sheets-Sheet l Dec. 24, 1968 E. J. M LAUGHLIN 3,413,622

LAMPHOLDER WITH MULTIPLE ARRANGEMENT OF COMPONENTS Filed Jan. 12, 1967 s Sheets-Sheet 2 Dec. 24, 1968 E. J. MCLAUGHUN 3,4 ,6 2

LAMPHOLDER WITH MULTIPLE ARRANGEMENT OF COMPONENTS Filed Jan. 12, 1967 5 Sheets-Sheet 3 FIG.6. FIG.7.

United States Patent 1 3,418,622 LAMPHOLDER WITH MULTIPLE ARRANGEMENT OF COMPONENTS Emmett .I. McLaughlin, Fairfield, C0nn., assignor to Westinghouse Electric Corporation, Pittsburgh, Pa., a corporation of Pennsylvania Filed Jan. 12, 1967, Ser. No. 608,852 4 Claims. (Cl. 339-56) ABSTRACT OF THE DISCLOSURE The present invention concerns a fluorescent tube lampholding device in which a single lampholding unit can be assembled to provide either an axially movable plunger type holder or a fixed type holder while simultaneously providing for the angular displacement of the lampholder terminals so that the fluorescent tube lamp to be supported between two of the novel holders can assume any one of a plurality of angular, light directing positions. This is accomplished by using identical parts for both types of holders which include a plunger structure containing the terminals, and a cylindrical shaped opening extending through a housing adapted to receive and mutually engage the plunger in any of a plurality of angular positions.

The present invention relates generally to fluorescent tube lampholders and particularly to a versatile arrangement of lampholder components which permits a variety of constructions with a minimum of parts.

Fluorescent tube lamp fixtures employ lampholders that generally provide for quick and easy insertion and removal of the fluorescent tube lamps. One type of fixture accomplishes this by using a movable type holder on one end and a fixed holder on the other end, the movable type usually employing an axially displaceable, spring-biased plunger. The lamp is inserted by first placing one of its ends against the plunger, and then forcing the plunger inwardly against the spring pressure until the other end of the lamp is aligned with the fixed holder at which time the plunger is allowed to return until the lamp is held securely between the holders. It is this type of lampholder that the present invention is concerned.

Another concern of the present invention is the development of more efficient, increased light output fluorescent lamps. With such lamps it is often necessary to provide lampholders which will provide angular or rotational positioning of the plungers within the holders so that light from the lamps is made directional in relation to the plane of the fixture and its reflector.

Briefly, in accordance with the principles of the present invention, the above described developments from the basis of a novel lampholding device in which the same components can be assembled to form either an axially movable plunger type lamp-holder or a fixed type lampholder While simultaneously providing for the angular displacement of the lampholder terminal contacts so that the fluorescent tube to be supported between two of the novel holders can assume any one of a plurality of angular, light directing positions. This is accomplished by use of a molded plastic base or housing provided with a circular shaped opening and surface extending axially from the front to the back of the housing. The inside surface of the opening is provided with a plurality of ribs or raised portions extending substantially the axial length of the circular surface. Inside the opening is disposed a terminal supporting, cylindrical shaped plunger provided with molded peripheral projections positioned to engage the axially extending ribs. The ribs and projections are located in such a manner that the ice plunger can be held completely within the housing with the terminals disposed in any of a plurality of fixed angular positions as a stationary holder for one end of a fluorescent lamp, or the plunger can be allowed to extend beyond the front of the housing in an axially displaceable manner in the same plurality of angular positions. In its extended, displaceable position, the plunger is spring-biased so that a fluorescent lamp may be used to force the plunger into the housing When the lamp is inserted between two of the novel holders.

Thus, the one plunger and housing of the present invention can be assembled to provide both a fixed or movable plunger while simultaneously providing a plurality of angular or rotational positions for the terminals in the plunger thereby allowing fluorescent lamp terminals to make electrical contact with the plunger terminals in any one of a plurality of angular positions.

It is therefore an object of the present invention to provide a versatile fluorescent tube lampholder in which the same parts can be assembled to provide a fixed or movable type lampholder, and a choice of angular terminal positions with each type.

This and other objects and advantages of the invention will become more apparent upon consideration of the following detailed description along with the accompanying drawings, in which:

FIG. 1 is an exploded isometric view of a lampholder constructed in accordance with the principles of the present invention;

FIG. 2 is a partial rear elevation view of the housing structure of the lampholder shown in FIG. 1;

FIG. 3 is a cross-sectional view of the housing structure taken along line IIIII'I of FIG. 2 with the inside of the housing shown in elevation;

FIG. 4 shows four partial rear elevation views of the housing structure of FIG. 1 supporting a plunger in four different angular positions in a fixed manner;

FIG. 5 shows four elevation views of the plunger of FIG. 4 supported in four different angular positions in the housing structure of FIG. 1 in an axially displaceable manner;

FIG. 6 is a side elevation view of the assembled lampholder of the present invention with portions thereof shown in cross-section, and a plunger utilized in the lampholder of FIG. 1 in the fixed manner of FIG. 4;

FIG. 7 is another side elevation View of the lampholder of FIG. 1 with the plunger shown in an extended position and the displaceable manner of FIG. 5;

FIG. 8 is a rear end elevation view of the plunger employed in the lampholder of the invention;

FIG. 9 is a cross-sectional view of the plunger shown in FIG. 8;

FIG. 10 is a front end elevation view of the plunger shown in FIGS. 8 and 9;

FIG. 11 is a front elevation view of the lampholder of the invention; and

FIG. 12 is an inside view of the cover structure shown in FIG. 1 with certain additional elements associated therewith shown in elevation.

Specifically, FIG. 1 shows a lampholder 10 comprising an insulating housing or base 12 and an insulating cover member 14. The housing and cover member are held together by a threaded bolt 16 or other suitable attaching means. FIGS. 6 and 7 show the cover and housing secured together to form a unitary lampholding structure 10, two of which would be employed to support a fluorescent lamp (not shown) between them.

The housing 12 is provided with an open back, which is designed to be covered by the cover member 14, and a circular opening or chamber 18 extending through the housing and adapted to receive a cylindrical shaped,

3 insulating plunger means 20. FIGS. 4 through 7 show the plunger in place in the housing 12.

The inside surface which forms the circular opening 18 is provided with a plurality of axially extending rib portions generally designated 22. In the figure, eight rib portions are shown though the invention is not limited thereto. One half of the number of ribs (four) are dimensionally uniform throughout their length, as best seen in FIG. 1, and are disposed about one half of the inside circular surface of the opening 18. The other half of the circular surface is occupied by four rib portions provided with a wide dimension 24 so that said rib portions have an L-shape at one end thereof as best seen in FIG. 3. An end view of the two different rib dimensions is seen in FIG. 2 with the narrow, uniform ribs labelled 22 and the wider ribs labelled 24.

By virtue of the wide L-shaped rib 24, a ledge 25 is formed, the plane of which lies perpendicular to the axis and curved surface of the opening 18 as best seen in FIGS. 2 and 3. The ledge 25 is employed to hold the plunger 20 within the housing 12 as a stationary lampholding means in a manner presently to be explained.

As best seen in the isometric view of FIG. 1, the insulating plunger 20 is provided with a pair of projections 26 and a single projection 28 disposed substantially opposite thereto. The projections are formed on the outside peripheral surface and adjacent the rear end of the plunger. The projections 26 and 28 have a depth dimension corresponding to that of the ribs 22 in the opening 18 of the housing 12 with the pair of projections 26 forming a groove or slot 27 having a similar depth dimension as best seen in FIGS. 4 and 5.

The width of the slot 27 corresponds to the width of the ribs 22 so that when the plunger 20 is placed in the opening 18, the slot 27 can engage any one of the ribs and slide therealong, see again FIGS. 4 and 5. FIGS. 4 and show further the projections 26 and 28 spaced about the periphery of the plunger in such a manner that when the pair of projections 26 straddle any one of the ribs 22 so that the straddled rib is disposed in slot 27, the single projection 28 will be disposed adjacent the rib which is substantially diametrically opposite to the one in the slot. When the slot 27 engages any one of the ribs 22 having the narrow uniform dimension (FIG. 5), the single projection 28 lies in the open space between two of the ribs having the wide, L-shaped dimensions 24. With the projections 26 and 28 so disposed, the plunger is allowed to travel through the opening 18 until the projections are caught on a circumferential flange 30 extending inwardy into the opening adjacent the front end of the housing 12 as best seen in FIG. 7. In this position, a substantial portion of the plunger body extends beyond the front end of the housing so that the plunger can function as an axially movable lampholder in a manner to be more fully explained. The plunger is held against rotational movement by the projections 26 and the rib engaged by said projections.

To assemble the plunger 20 so that it functions as a fixed lampholder (FIG. 4), the plunger is rotated and inserted in the opening 18 of the housing 12 so that the projections 26 straddle the narrow end of the ribs 22 having the wide section 24 when the plunger is returned to the housing. As the plunger is moved towards the front of the housing, one of the projections 26 engages the ledge 25 so that the plunger is prevented from further advance ment. This is best seen in FIG. 6; as seen, a major portion of the plunger body is contained within the housing 12. When the cover 14 is fastened to the housing, the plunger is prevented from axial movement by the cover and the engagement between the ledge 25 and the one projection 26 disposed thereagainst. The plunger is prevented from rotational movement by the engagement between the projections 26 and the straddled rib 22 as explained above.

Since the engaging structures of the plunger 20 and the housing 12 (i.e., projections 26 and 28, and ribs 22 and 24) are disposed oppositely around the plunger and the circular opening 18 respectively, mere rotation of the plunger by a suflicient angle before it is inserted into the opening, provides the choice of a fixed or movable lampholding device when the lampholder 10 is assembled.

Two of the plungers 20, as part of two lampholders 10, function to support a fluorescent tube lamp (not shown) between them with one of the plungers disposed in a housing 12 in fixed position, and one of the plungers disposed in a housing 12 in an axially displaceable manner as shown in FIGS. 6 and 7, respectively.

The body of the plunger 20 is provided with two diametrically spaced cylindrically shaped recesses 32 extending part way into the plunger body from the rear end thereof as seen in FIGS. 8 and 9. The plunger 20 is further provided with an elongated oval recess 34 which extends inwardly from the front end of the plunger as seen in FIGS. 9 and 10. The axis of the oval recess is coincident with the diameter of the plunger on which the cylindrical recesses 32 are located, with the inner ends of the recesses 32 and 34 being spaced apart to form an integral barrier 35 between them.

The two cylindrical recesses 32 further form an integral partition 36 therebetween which extends into the oval recess 34 along the axis of the plunger as best seen in FIG. 9. In the oval recess 34, the partition 36 is provided with an enlarged body portion 38 shown in elevation in FIGS. 9 and 10. The enlarged portion is provided with two axially extending grooves 39 formed in alignment with two elongated rectangular shaped slots 40 provided in the partition 35, separated by the axial partition 36 and extending in the direction of the diameter of the plunger on which the recesses 32 and recess 34 are located. The grooves 39 and slots 40 are designed to support terminal means in a manner presently to be explained.

As explained earlier, movable plunger devices are generally spring-biased to allow insertion of the fluorescent tube lamp and to hold the lamp in place after the insertion thereof. In the present invention, the plunger 20 is spring-biased by two helical springs 42 having circumferential dimensions corresponding to those of the cylindrical recesses 32. The springs 42 are shown provided with V-shaped extension 43 at one end thereof which serve as contact means when disposed in the plunger 20 as shown in FIGS. 6, 7 and 11. The springs 42 and their V-shaped extensions 43 are illustrative only; other types of spring-biased contacts may be employed in place thereof.

The springs are disposed in the cylindrical recesses 32 with the V-shaped extensions protruding through the slotted openings 40 and into the oval shaped recess 34. One side of the V-shaped extensions 43 are further supported in the grooves 39 provided in the partition 36. When the cover 14 is placed on and secured to the housing 12, the springs 42 are compressed between the cover and the vertical partition 35 as best seen in FIGS. 6 and 7. With the plunger 20 mounted in a fixed position (FIGS. 4 and 6) the springs bias the plunger against small movements within the circular opening 18 in the housing 12. When the plunger is mounted in position for axial displacement (FIGS. 5 and 7) the springs 42 provide a resilient bias that allows the plunger to move in the housing when a lamp to be held thereby is inserted thereagainst.

In its fixed position, the plunger 20 may be provided with springs that are shorter in length than the ones employed in the plunger mounted for axial displacement. This would facilitate assembly of the lampholder 10 when it is employed as a fixed lampholding device while a longer spring would provide adequate bias on the plunger when the lampholder is to function in a movable manner.

To energize the lamp held by the lampholders 10, the lampholders are provided with a pair of metallic terminal contact blades or strips, generally designated 45, having straight blade portion 46 adjacent one end thereof and wire engagement spring arms 47 and 48 at the other end thereof as best seen in FIG. 1. The contact strips 45 are held in position in the cover 14 and exposed in a frontal direction towards the housing 12 for engaging the helical springs 42 along the contact portions 46 of the strips as shown in the plan view of FIG. 12.

The blade portions 46- are disposed in slotted recesses 50 provided in a raised circular platform structure 51 molded on the inside surface of the cover 14 as best seen in FIG. 1. The face of the platform 51 is provided with a circular array of eight projections or posts 52 with another post 53 disposed in the center of the circular array. The blade portions 46 of the terminal strips 45 lie between the posts 52 when disposed in the cover 14- and in the slotted recesses.50 in the platform 51 as seen in FIG. 12. When the helical springs 42 are disposed in the cylindrical recesses of the plunger 20 and the cover 14, containing the terminal strips 45, is placed over the back of the housing 12, the end convolutions of the springs automatically locate over two diametrically opposed posts 52 as shown in FIG. 12. The exposed edge of each of the blades 46 lies in a plane above that of the circular platform but below the tops of the posts '52 and 53 so that the end convolution of each spring 42 is in physical and electrical contact with the exposed blade edge. The center post 53 and the two posts 52 on the outside periphery of the springs maintain the springs in proper alignment and in electrical insulation from each other.

With such an arrangement in the cover 14, the plunger 20, containing the springs 42 with contact extensions 43, can assume any of the angular positions shown in FIGS. 4 and 5 while simultaneously maintaining the springs in electrical contact with the blade portions 46' of the conducting strips 45. In any of the angular positions, two diametrically opposed posts 52 are available to project into the springs 42 to maintain each spring in alignment over the exposed edge of its respective blade 46. The compression of each spring between its respective blade and the partition 35' in housing 12 maintains the blades 46' and springs 42 in electrical contact as mentioned earlier.

Power is applied to lampholder by lead wires (not shown) retained by the ends of the wire engagement arms 47 and 48. This is accomplished by wire bracing surfaces 55 and 56 disposed opposite the respective ends of the engagement arms and in alignment with openings 58 provided in end face 59 of the cover 14. Lead wires with 'bared ends are inserted through the openings 58 and between the ends of the engagement arms and the wire bracing surfaces, the bare ends being pressed against the surfaces by virtue of a spring force in the arms 47 and 48 which are inwardly deflected by the inserted wires. The arms 47 and 48 of terminal strip 45 and the springs 42, all being made of suitable metal, function as an electrically conductive path to the terminals of the lamp in contact with the contact extensions 43 of the springs when the lamp is supported between two of the lampholders 10.

The sides of the housing 12. and cover 14 adjacent their upper (base) ends are provided with axially extending slots 62 and 64, respectively, for receiving the edges of a sheet metal panel in the fixture (not shown) to which the lampholder 10 is attached. The lampholder 10 is thereby permitted to slide into a cut-out portion provided in the metal panel so that auxiliary fasteners (screws, nuts, rivets etc.) are not needed to attach the lampholders to the fixtures during the assembly thereof.

To further secure lampholder 10 in a fixture, a small rib means 63 is provided at the inner end of the slot 64 as best seen in FIGS. 7 and 12. In the figures, only the one slot in the cover 14 is so provided. Obviously, however, both of the slots 64 in the cover, and both of the slots 62 in the housing 12 may be provided with such a rib means.

The rib means 63 may further be tapered off in a forward axial direction so that the rib means extends only part way of the length of the slot 64 as seen in FIG. 7.

When the lampholder 10 is inserted in the cut-out portion in the fixture, and directed to the rear thereof, the rib 63 will bind against the edges of the cut-out portion if the lampholder with the rib is wider than the cutout. Thus, each lampholder is quickly and easily secured in the fixture so that during assembly thereof, and when operations are performed thereon, the operation will not be hampered by loose lampholders falling from their place in the fixture.

It should now be apparent from the foregoing description that a new, useful and highly versatile fluorescent tube lampholding device has been disclosed, and that the versatility has beenattained with a minimum of inexpensive parts. This has been accomplished essentially by a single plunger means, and a cylindrical shaped opening provided within a single lampholding housing structure 12 adapted to receive and mutually engage the plunger in a multiplicity of angular dispositions. Simple rotation of the plunger provides options for a fixed or displaceable plunger containing contacts 43 disposed in a multiplicity of rotational or angular positions when the lampholding device is assembled. This in turn allows flexibility in design and use of fluorescent tube lamps such as when the lamps are angularly positioned for directing their light on a specific area.

While the invention has been described in connection with a preferred embodiment, it will be understood that it is not intended to be limited to the particular embodiment illustrated but is intended to cover alternative and equivalent constructions falling with in the spirit and scope of the appended claims.

What is claimed is:

1. A lampholder adapted to be assembled in either a fixed or resilient manner, said lampholder comprising:

an insulating housing with two opposed sides thereof having at least one opening therein, said openings being in axial alignment with each other, and

a chamber defined by an inside surface extending through said housing and between said openings,

an insulating plunger for slidable mounting in said chamber with electrical contact means supported in said plunger,

electrical conductor means for mechanically biasing said plunger and contact means in a direction along the plunger axis,

mutually engageable means provided on said inside surface and on said plunger for limiting the axial movement of said plunger through said chamber in at least two different axial positions,

engageable means disposed about the said inside surface for mutually engaging the means provided on said plunger in any of a plurality of angular positions of said plunger in either of said axial positions, an insulating cover member for said housing, terminal contact blades supported in said cover member, and

means provided on said cover member for locating said biasing means in electrical contact with said blades, and in adjacent angular positions having an uninterrupted sequence when moving from one angular position to the next through a 360 degree rotation of said plunger and biasing means,

said locating structure further permitting an exchange of electrical contact between said blades and biasing means when said biasing means is rotated through predetermined angular positions.

2. The lampholder recited in claim 1 in which the insulating cover is provided with a raised portion on the inside surface thereof:

said raised portion having a face portion facing in the direction of the chamber in the housing when the housing and cover are placed together, and

at least two slotted recesses formed in said raised portion for accommodating the terminal contact blades in an edgewise manner to provide exposed edges facing the chamber in the housing,

the means for locating the biasing means comprising a plurality of outwardly extending projections provided on the face portion of said raised portion, the projections being located about said slotted recesses to locate the biasing means against the exposed edges in all of the angular positions of the plunger and biasing means.

3. The lampholder recited in claim 1 in which the structure for locating the biasing means comprises a circular array of eight outwardly extending projections:

said projections located about the terminal contact blades in a manner to provide the uninterrupted sequence of angular positions for the biasing means.

4. The lampholder recited in claim 1 in which the insulating cover is provided with a base portion having inwardly directed slots formed in at least two opposed sides thereof:

at least one of said slots having an integral rib portion extending outwardly from the inner end of said slot.

References Cited UNITED STATES PATENTS 2,883,639 4/1959 Kulka 33956 3,138,418 6/1964 Dazley et al. 339-50 3,290,638 12/1966 Pistey 33956 3,305,823 2/1967 Dahlhaus et al. 339-53 FOREIGN PATENTS 1,198,931 8/1965 Germany.

646,634 10/1962 Italy.

MARVIN A. CHAMPION, Primary Examiner.

20 JOSEPH H. MCGLYNN, Assistant Examiner. 

